project NA-200 bhp

[fzr phil]

i'm not worthy!

[MGaz]

Yes, you do have a Chrome- Moly crank which is VERY strong, not a diesel one. And yes, the botom end will probably handle 8000rpm. The only thing i'm not sure about are the valve springs, not sure if they are stiff enough for 8000rpm.

8000rpm ?

well, seeing as i don't know what valve springs i have (maybe james or someone could tell me) I think i'll resist the temptation for now.

would 7000rpm be 'OK' tho, while i'm un aware of what valve springs i have?

Just so i know, what's the worst that could happen?

[stiglet]

I'm not sure what will happen if you have too much rpm, i'm guessing you'll get valve float and the piston's could hit the valves? The original KV is a non-interference engine but i'm not sure about the GTi as they increased the compression ratio too i beleive. It could lean out also. I'll let one of the more experienced forum users answer that one.

I'm not sure if higher rpm's are the way forward though as even the gti head could be strangling the engine at that point. I suggest cams only because i know the standard ones (which i think the gti still uses) are very very tame and you're only 20bhp off. As Mr. Casey mentions, better to make use of the monster torque it already has. Have you looked into better fuel injection and spark? I know the K-jet is bullit proof but it will never give as good a mix as the actual high pressure injection i don't think.

What do others suggest?

[anton]

i had some schick 285 cams in my 10v and that had a very nice power delivery, coupled with the 2.5 block it will be even more drivable. my car was fine on the road, less low don grunt, but then what you loose you've made up for with the gti block. but even my 285 cams were running out of steam about 7k....dont think you'll get any benefit over 7500, or 7000 for that matter. plus you'll struggle to be able to push a 10v that high....engine note gives of a sound that makes you feel like your killing a small kitten you just cant do it! it sounds so wrong!

i recon 7-7.5k rpm and some cams with a nice exhaust will sort you out tho.

Ant

[Acidburn]

engine note gives of a sound that makes you feel like your killing a small kitten you just cant do it! it sounds so wrong!

Ant

Thought this would not bother you, like the sound of smashing glass, its just another day in the life of ant.

I agree with the above and that around 7000-7200 would be the most i'd be tempted to rev a 10v. That should be all you'd need.

[anton]

Thought this would not bother you, like the sound of smashing glass, its just another day in the life of ant.

you got to admit, it made the day more interesting lol you should have seen how i took off alex's downpipe!

another thing to remember about our engine.....forget 20v, if you can make a 10v as good as powerful as a 20v then it will a) have more low down grunt, even with a fairly agressive cam! and b) it will sound SOOOOO much better!!!

Ant

[Acidburn]

Lol i've all ready heard how you removed the manifold

Agree, the 10'v will sound more better everyday of the week plus does not need revving as hard as a 20v to produce the goods.

[MGaz]

Thought this would not bother you, like the sound of smashing glass, its just another day in the life of ant.

I agree with the above and that around 7000-7200 would be the most i'd be tempted to rev a 10v. That should be all you'd need.

any recommendations on a rotor arm then? or is there no difference in who makes them?

i've noticed that halfords do a section of rotor arms, some have different rev limits printed on them by looks of it. Will any of them fit ok?

or is it better to use a narrower rotor arm 'without' the sliding part on it? Cause at the moment i'm using one of the wider type with a sliding part. But mine has quite a low rev limit

[stiglet]

I'm sure the standard rev limit of all the KV's is around 6grand, maybe 6+half, not sure about 7. I had a rotor arm without the mechanism in mine effectively removing the limiter. I can't remember if it actually worked as i never revved it past 6 anyway, but as long as there isn't anything else regulating the rev's that should be all you need.

[MGaz]

I'm sure the standard rev limit of all the KV's is around 6grand, maybe 6+half, not sure about 7. I had a rotor arm without the mechanism in mine effectively removing the limiter. I can't remember if it actually worked as i never revved it past 6 anyway, but as long as there isn't anything else regulating the rev's that should be all you need.

ok.. i tried using the narrower type rotor arm (with out the sliding rev limit part) and it doesn't seem to want to rev any higher than about 6850rpm. ???

so what could be limiting it? is there some kind of 'secondary' rev limiter on these cars somewhere?

[kwlw]

ok.. i tried using the narrower type rotor arm (with out the sliding rev limit part) and it doesn't seem to want to rev any higher than about 6850rpm. ???

so what could be limiting it? is there some kind of 'secondary' rev limiter on these cars somewhere?

Fuel pump relay. Some or all of them have rpm input on KV's. There are ones which limit rpm, and ones which don't. No Idea which is is which.

You can test with wire plugged instead of relay. I mean pull out relay, plug wire instead of relay, do a test run. Fuel pump will work all the time. If rpm limit disappear - then it's the relay which needs to be tweaked. Maybe some electronic guru can do it (by adding let's say logic divider to it's schematics).

Relay just does cut out of fuel supply (you feel it). If you just reacing limit, then it's cams or measurement plate.

Sau

[stiglet]

Fuel pump relay. Some or all of them have rpm input on KV's. There are ones which limit rpm, and ones which don't. No Idea which is is which.

You can test with wire plugged instead of relay. I mean pull out relay, plug wire instead of relay, do a test run. Fuel pump will work all the time. If rpm limit disappear - then it's the relay which needs to be tweaked. Maybe some electronic guru can do it (by adding let's say logic divider to it's schematics).

Relay just does cut out of fuel supply (you feel it). If you just reacing limit, then it's cams or measurement plate.

Sau

that's useful, i never knew the KV had a second limiter! Should be easy to tell if it's fuel cut off or just running out of steam. Is it quite a violent cut-off when it reaches the limit?

Could it be possible that audi switched over from a rotor arm limiter to the fuel relay limter (or the other way around) so all you need is the corresponding relay from one year of manufacture, and the rotor arm from another (witch you already have) and that would solve the problem.

Incidently, does it still pull well at 6000rpm?